class_name SystemDock
extends Control
## The slide-in system dock (mock 2a): a gold handle toggles a column of screen
## buttons in/out. §2: state (owns the open toggle via ShellState). The buttons
## are the routing seam — they emit screen_requested; the screens they open land
## in later milestones, so the signal is currently a no-op for the shell.
##
## Layout is authored in SystemDock.tscn (editor-previewable). This script only
## wires the buttons' signals, drives the slide animation, and toggles state. Each
## dock button carries a `screen_id` StringName in its scene metadata; add/reorder
## buttons in the editor and the wiring follows.

signal screen_requested(id: StringName)

const SLIDE_SECONDS := 0.32
const HIDDEN_SHIFT := 230.0

var _screen_buttons: Dictionary = {}
var _state: ShellState
var _menu_open_pos: Vector2

@onready var _menu: VBoxContainer = $Menu
@onready var _handle: Button = $Handle


func _ready() -> void:
	# The buttons live in the scene; harvest each one's authored screen_id so the
	# routing seam follows editor edits (add/remove/reorder needs no code change).
	for child in _menu.get_children():
		if child is Button and child.has_meta("screen_id"):
			var id: StringName = child.get_meta("screen_id")
			child.pressed.connect(func(): screen_requested.emit(id))
			_screen_buttons[id] = child
	_handle.pressed.connect(_on_handle_pressed)
	# Capture the authored open position so the slide is relative to wherever the
	# menu is placed in the editor — moving it in the editor just works.
	_menu_open_pos = _menu.position


func setup(state: ShellState) -> void:
	_state = state
	_apply_open(_state.dock_open)


func _on_handle_pressed() -> void:
	if _state == null:
		return
	_apply_open(_state.toggle_dock())


func _apply_open(open: bool) -> void:
	_handle.text = "›" if open else "‹"
	var target := _menu_open_pos if open else _menu_open_pos + Vector2(HIDDEN_SHIFT, 0.0)
	var alpha := 1.0 if open else 0.0
	if not is_inside_tree():
		_menu.position = target
		_menu.modulate.a = alpha
		return
	var tween := create_tween().set_parallel(true)
	tween.tween_property(_menu, "position", target, SLIDE_SECONDS)
	tween.tween_property(_menu, "modulate:a", alpha, SLIDE_SECONDS)